fs/xfs/xfs_rtalloc.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_types.h"
  21 #include "xfs_bit.h"
  22 #include "xfs_log.h"
  23 #include "xfs_inum.h"
  24 #include "xfs_trans.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_ag.h"
  27 #include "xfs_dir2.h"
  28 #include "xfs_mount.h"
  29 #include "xfs_bmap_btree.h"
  30 #include "xfs_dinode.h"
  31 #include "xfs_inode.h"
  32 #include "xfs_alloc.h"
  33 #include "xfs_bmap.h"
  34 #include "xfs_rtalloc.h"
  35 #include "xfs_fsops.h"
  36 #include "xfs_error.h"
  37 #include "xfs_rw.h"
  38 #include "xfs_inode_item.h"
  39 #include "xfs_trans_space.h"
  40 #include "xfs_utils.h"
  41 #include "xfs_trace.h"
  42 #include "xfs_buf.h"
  43
  44
  45 /*
  46  * Prototypes for internal functions.
  47  */
  48
  49
  50 STATIC int xfs_rtallocate_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  51                 xfs_extlen_t, xfs_buf_t **, xfs_fsblock_t *);
  52 STATIC int xfs_rtany_summary(xfs_mount_t *, xfs_trans_t *, int, int,
  53                 xfs_rtblock_t, xfs_buf_t **, xfs_fsblock_t *, int *);
  54 STATIC int xfs_rtcheck_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  55                 xfs_extlen_t, int, xfs_rtblock_t *, int *);
  56 STATIC int xfs_rtfind_back(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  57                 xfs_rtblock_t, xfs_rtblock_t *);
  58 STATIC int xfs_rtfind_forw(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  59                 xfs_rtblock_t, xfs_rtblock_t *);
  60 STATIC int xfs_rtget_summary( xfs_mount_t *, xfs_trans_t *, int,
  61                 xfs_rtblock_t, xfs_buf_t **, xfs_fsblock_t *, xfs_suminfo_t *);
  62 STATIC int xfs_rtmodify_range(xfs_mount_t *, xfs_trans_t *, xfs_rtblock_t,
  63                 xfs_extlen_t, int);
  64 STATIC int xfs_rtmodify_summary(xfs_mount_t *, xfs_trans_t *, int,
  65                 xfs_rtblock_t, int, xfs_buf_t **, xfs_fsblock_t *);
  66
  67 /*
  68  * Internal functions.
  69  */
  70
  71 /*
  72  * Allocate space to the bitmap or summary file, and zero it, for growfs.
  73  */
  74 STATIC int                              /* error */
  75 xfs_growfs_rt_alloc(
  76         xfs_mount_t     *mp,            /* file system mount point */
  77         xfs_extlen_t    oblocks,        /* old count of blocks */
  78         xfs_extlen_t    nblocks,        /* new count of blocks */
  79         xfs_ino_t       ino)            /* inode number (bitmap/summary) */
  80 {
  81         xfs_fileoff_t   bno;            /* block number in file */
  82         xfs_buf_t       *bp;            /* temporary buffer for zeroing */
  83         int             committed;      /* transaction committed flag */
  84         xfs_daddr_t     d;              /* disk block address */
  85         int             error;          /* error return value */
  86         xfs_fsblock_t   firstblock;     /* first block allocated in xaction */
  87         xfs_bmap_free_t flist;          /* list of freed blocks */
  88         xfs_fsblock_t   fsbno;          /* filesystem block for bno */
  89         xfs_inode_t     *ip;            /* pointer to incore inode */
  90         xfs_bmbt_irec_t map;            /* block map output */
  91         int             nmap;           /* number of block maps */
  92         int             resblks;        /* space reservation */
  93
  94         /*
  95          * Allocate space to the file, as necessary.
  96          */
  97         while (oblocks < nblocks) {
  98                 int             cancelflags = 0;
  99                 xfs_trans_t     *tp;
 100
 101                 tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_ALLOC);
 102                 resblks = XFS_GROWFSRT_SPACE_RES(mp, nblocks - oblocks);
 103                 /*
 104                  * Reserve space & log for one extent added to the file.
 105                  */
 106                 if ((error = xfs_trans_reserve(tp, resblks,
 107                                 XFS_GROWRTALLOC_LOG_RES(mp), 0,
 108                                 XFS_TRANS_PERM_LOG_RES,
 109                                 XFS_DEFAULT_PERM_LOG_COUNT)))
 110                         goto error_cancel;
 111                 cancelflags = XFS_TRANS_RELEASE_LOG_RES;
 112                 /*
 113                  * Lock the inode.
 114                  */
 115                 if ((error = xfs_trans_iget(mp, tp, ino, 0,
 116                                                 XFS_ILOCK_EXCL, &ip)))
 117                         goto error_cancel;
 118                 xfs_bmap_init(&flist, &firstblock);
 119                 /*
 120                  * Allocate blocks to the bitmap file.
 121                  */
 122                 nmap = 1;
 123                 cancelflags |= XFS_TRANS_ABORT;
 124                 error = xfs_bmapi(tp, ip, oblocks, nblocks - oblocks,
 125                         XFS_BMAPI_WRITE | XFS_BMAPI_METADATA, &firstblock,
 126                         resblks, &map, &nmap, &flist);
 127                 if (!error && nmap < 1)
 128                         error = XFS_ERROR(ENOSPC);
 129                 if (error)
 130                         goto error_cancel;
 131                 /*
 132                  * Free any blocks freed up in the transaction, then commit.
 133                  */
 134                 error = xfs_bmap_finish(&tp, &flist, &committed);
 135                 if (error)
 136                         goto error_cancel;
 137                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 138                 if (error)
 139                         goto error;
 140                 /*
 141                  * Now we need to clear the allocated blocks.
 142                  * Do this one block per transaction, to keep it simple.
 143                  */
 144                 cancelflags = 0;
 145                 for (bno = map.br_startoff, fsbno = map.br_startblock;
 146                      bno < map.br_startoff + map.br_blockcount;
 147                      bno++, fsbno++) {
 148                         tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_ZERO);
 149                         /*
 150                          * Reserve log for one block zeroing.
 151                          */
 152                         if ((error = xfs_trans_reserve(tp, 0,
 153                                         XFS_GROWRTZERO_LOG_RES(mp), 0, 0, 0)))
 154                                 goto error_cancel;
 155                         /*
 156                          * Lock the bitmap inode.
 157                          */
 158                         if ((error = xfs_trans_iget(mp, tp, ino, 0,
 159                                                         XFS_ILOCK_EXCL, &ip)))
 160                                 goto error_cancel;
 161                         /*
 162                          * Get a buffer for the block.
 163                          */
 164                         d = XFS_FSB_TO_DADDR(mp, fsbno);
 165                         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
 166                                 mp->m_bsize, 0);
 167                         if (bp == NULL) {
 168                                 error = XFS_ERROR(EIO);
 169 error_cancel:
 170                                 xfs_trans_cancel(tp, cancelflags);
 171                                 goto error;
 172                         }
 173                         memset(XFS_BUF_PTR(bp), 0, mp->m_sb.sb_blocksize);
 174                         xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
 175                         /*
 176                          * Commit the transaction.
 177                          */
 178                         error = xfs_trans_commit(tp, 0);
 179                         if (error)
 180                                 goto error;
 181                 }
 182                 /*
 183                  * Go on to the next extent, if any.
 184                  */
 185                 oblocks = map.br_startoff + map.br_blockcount;
 186         }
 187         return 0;
 188 error:
 189         return error;
 190 }
 191
 192 /*
 193  * Attempt to allocate an extent minlen<=len<=maxlen starting from
 194  * bitmap block bbno.  If we don't get maxlen then use prod to trim
 195  * the length, if given.  Returns error; returns starting block in *rtblock.
 196  * The lengths are all in rtextents.
 197  */
 198 STATIC int                              /* error */
 199 xfs_rtallocate_extent_block(
 200         xfs_mount_t     *mp,            /* file system mount point */
 201         xfs_trans_t     *tp,            /* transaction pointer */
 202         xfs_rtblock_t   bbno,           /* bitmap block number */
 203         xfs_extlen_t    minlen,         /* minimum length to allocate */
 204         xfs_extlen_t    maxlen,         /* maximum length to allocate */
 205         xfs_extlen_t    *len,           /* out: actual length allocated */
 206         xfs_rtblock_t   *nextp,         /* out: next block to try */
 207         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 208         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 209         xfs_extlen_t    prod,           /* extent product factor */
 210         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
 211 {
 212         xfs_rtblock_t   besti;          /* best rtblock found so far */
 213         xfs_rtblock_t   bestlen;        /* best length found so far */
 214         xfs_rtblock_t   end;            /* last rtblock in chunk */
 215         int             error;          /* error value */
 216         xfs_rtblock_t   i;              /* current rtblock trying */
 217         xfs_rtblock_t   next;           /* next rtblock to try */
 218         int             stat;           /* status from internal calls */
 219
 220         /*
 221          * Loop over all the extents starting in this bitmap block,
 222          * looking for one that's long enough.
 223          */
 224         for (i = XFS_BLOCKTOBIT(mp, bbno), besti = -1, bestlen = 0,
 225                 end = XFS_BLOCKTOBIT(mp, bbno + 1) - 1;
 226              i <= end;
 227              i++) {
 228                 /*
 229                  * See if there's a free extent of maxlen starting at i.
 230                  * If it's not so then next will contain the first non-free.
 231                  */
 232                 error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, &next, &stat);
 233                 if (error) {
 234                         return error;
 235                 }
 236                 if (stat) {
 237                         /*
 238                          * i for maxlen is all free, allocate and return that.
 239                          */
 240                         error = xfs_rtallocate_range(mp, tp, i, maxlen, rbpp,
 241                                 rsb);
 242                         if (error) {
 243                                 return error;
 244                         }
 245                         *len = maxlen;
 246                         *rtblock = i;
 247                         return 0;
 248                 }
 249                 /*
 250                  * In the case where we have a variable-sized allocation
 251                  * request, figure out how big this free piece is,
 252                  * and if it's big enough for the minimum, and the best
 253                  * so far, remember it.
 254                  */
 255                 if (minlen < maxlen) {
 256                         xfs_rtblock_t   thislen;        /* this extent size */
 257
 258                         thislen = next - i;
 259                         if (thislen >= minlen && thislen > bestlen) {
 260                                 besti = i;
 261                                 bestlen = thislen;
 262                         }
 263                 }
 264                 /*
 265                  * If not done yet, find the start of the next free space.
 266                  */
 267                 if (next < end) {
 268                         error = xfs_rtfind_forw(mp, tp, next, end, &i);
 269                         if (error) {
 270                                 return error;
 271                         }
 272                 } else
 273                         break;
 274         }
 275         /*
 276          * Searched the whole thing & didn't find a maxlen free extent.
 277          */
 278         if (minlen < maxlen && besti != -1) {
 279                 xfs_extlen_t    p;      /* amount to trim length by */
 280
 281                 /*
 282                  * If size should be a multiple of prod, make that so.
 283                  */
 284                 if (prod > 1 && (p = do_mod(bestlen, prod)))
 285                         bestlen -= p;
 286                 /*
 287                  * Allocate besti for bestlen & return that.
 288                  */
 289                 error = xfs_rtallocate_range(mp, tp, besti, bestlen, rbpp, rsb);
 290                 if (error) {
 291                         return error;
 292                 }
 293                 *len = bestlen;
 294                 *rtblock = besti;
 295                 return 0;
 296         }
 297         /*
 298          * Allocation failed.  Set *nextp to the next block to try.
 299          */
 300         *nextp = next;
 301         *rtblock = NULLRTBLOCK;
 302         return 0;
 303 }
 304
 305 /*
 306  * Allocate an extent of length minlen<=len<=maxlen, starting at block
 307  * bno.  If we don't get maxlen then use prod to trim the length, if given.
 308  * Returns error; returns starting block in *rtblock.
 309  * The lengths are all in rtextents.
 310  */
 311 STATIC int                              /* error */
 312 xfs_rtallocate_extent_exact(
 313         xfs_mount_t     *mp,            /* file system mount point */
 314         xfs_trans_t     *tp,            /* transaction pointer */
 315         xfs_rtblock_t   bno,            /* starting block number to allocate */
 316         xfs_extlen_t    minlen,         /* minimum length to allocate */
 317         xfs_extlen_t    maxlen,         /* maximum length to allocate */
 318         xfs_extlen_t    *len,           /* out: actual length allocated */
 319         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 320         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 321         xfs_extlen_t    prod,           /* extent product factor */
 322         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
 323 {
 324         int             error;          /* error value */
 325         xfs_extlen_t    i;              /* extent length trimmed due to prod */
 326         int             isfree;         /* extent is free */
 327         xfs_rtblock_t   next;           /* next block to try (dummy) */
 328
 329         ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 330         /*
 331          * Check if the range in question (for maxlen) is free.
 332          */
 333         error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, &next, &isfree);
 334         if (error) {
 335                 return error;
 336         }
 337         if (isfree) {
 338                 /*
 339                  * If it is, allocate it and return success.
 340                  */
 341                 error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
 342                 if (error) {
 343                         return error;
 344                 }
 345                 *len = maxlen;
 346                 *rtblock = bno;
 347                 return 0;
 348         }
 349         /*
 350          * If not, allocate what there is, if it's at least minlen.
 351          */
 352         maxlen = next - bno;
 353         if (maxlen < minlen) {
 354                 /*
 355                  * Failed, return failure status.
 356                  */
 357                 *rtblock = NULLRTBLOCK;
 358                 return 0;
 359         }
 360         /*
 361          * Trim off tail of extent, if prod is specified.
 362          */
 363         if (prod > 1 && (i = maxlen % prod)) {
 364                 maxlen -= i;
 365                 if (maxlen < minlen) {
 366                         /*
 367                          * Now we can't do it, return failure status.
 368                          */
 369                         *rtblock = NULLRTBLOCK;
 370                         return 0;
 371                 }
 372         }
 373         /*
 374          * Allocate what we can and return it.
 375          */
 376         error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
 377         if (error) {
 378                 return error;
 379         }
 380         *len = maxlen;
 381         *rtblock = bno;
 382         return 0;
 383 }
 384
 385 /*
 386  * Allocate an extent of length minlen<=len<=maxlen, starting as near
 387  * to bno as possible.  If we don't get maxlen then use prod to trim
 388  * the length, if given.  The lengths are all in rtextents.
 389  */
 390 STATIC int                              /* error */
 391 xfs_rtallocate_extent_near(
 392         xfs_mount_t     *mp,            /* file system mount point */
 393         xfs_trans_t     *tp,            /* transaction pointer */
 394         xfs_rtblock_t   bno,            /* starting block number to allocate */
 395         xfs_extlen_t    minlen,         /* minimum length to allocate */
 396         xfs_extlen_t    maxlen,         /* maximum length to allocate */
 397         xfs_extlen_t    *len,           /* out: actual length allocated */
 398         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 399         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 400         xfs_extlen_t    prod,           /* extent product factor */
 401         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
 402 {
 403         int             any;            /* any useful extents from summary */
 404         xfs_rtblock_t   bbno;           /* bitmap block number */
 405         int             error;          /* error value */
 406         int             i;              /* bitmap block offset (loop control) */
 407         int             j;              /* secondary loop control */
 408         int             log2len;        /* log2 of minlen */
 409         xfs_rtblock_t   n;              /* next block to try */
 410         xfs_rtblock_t   r;              /* result block */
 411
 412         ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 413         /*
 414          * If the block number given is off the end, silently set it to
 415          * the last block.
 416          */
 417         if (bno >= mp->m_sb.sb_rextents)
 418                 bno = mp->m_sb.sb_rextents - 1;
 419         /*
 420          * Try the exact allocation first.
 421          */
 422         error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
 423                 rbpp, rsb, prod, &r);
 424         if (error) {
 425                 return error;
 426         }
 427         /*
 428          * If the exact allocation worked, return that.
 429          */
 430         if (r != NULLRTBLOCK) {
 431                 *rtblock = r;
 432                 return 0;
 433         }
 434         bbno = XFS_BITTOBLOCK(mp, bno);
 435         i = 0;
 436         ASSERT(minlen != 0);
 437         log2len = xfs_highbit32(minlen);
 438         /*
 439          * Loop over all bitmap blocks (bbno + i is current block).
 440          */
 441         for (;;) {
 442                 /*
 443                  * Get summary information of extents of all useful levels
 444                  * starting in this bitmap block.
 445                  */
 446                 error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
 447                         bbno + i, rbpp, rsb, &any);
 448                 if (error) {
 449                         return error;
 450                 }
 451                 /*
 452                  * If there are any useful extents starting here, try
 453                  * allocating one.
 454                  */
 455                 if (any) {
 456                         /*
 457                          * On the positive side of the starting location.
 458                          */
 459                         if (i >= 0) {
 460                                 /*
 461                                  * Try to allocate an extent starting in
 462                                  * this block.
 463                                  */
 464                                 error = xfs_rtallocate_extent_block(mp, tp,
 465                                         bbno + i, minlen, maxlen, len, &n, rbpp,
 466                                         rsb, prod, &r);
 467                                 if (error) {
 468                                         return error;
 469                                 }
 470                                 /*
 471                                  * If it worked, return it.
 472                                  */
 473                                 if (r != NULLRTBLOCK) {
 474                                         *rtblock = r;
 475                                         return 0;
 476                                 }
 477                         }
 478                         /*
 479                          * On the negative side of the starting location.
 480                          */
 481                         else {          /* i < 0 */
 482                                 /*
 483                                  * Loop backwards through the bitmap blocks from
 484                                  * the starting point-1 up to where we are now.
 485                                  * There should be an extent which ends in this
 486                                  * bitmap block and is long enough.
 487                                  */
 488                                 for (j = -1; j > i; j--) {
 489                                         /*
 490                                          * Grab the summary information for
 491                                          * this bitmap block.
 492                                          */
 493                                         error = xfs_rtany_summary(mp, tp,
 494                                                 log2len, mp->m_rsumlevels - 1,
 495                                                 bbno + j, rbpp, rsb, &any);
 496                                         if (error) {
 497                                                 return error;
 498                                         }
 499                                         /*
 500                                          * If there's no extent given in the
 501                                          * summary that means the extent we
 502                                          * found must carry over from an
 503                                          * earlier block.  If there is an
 504                                          * extent given, we've already tried
 505                                          * that allocation, don't do it again.
 506                                          */
 507                                         if (any)
 508                                                 continue;
 509                                         error = xfs_rtallocate_extent_block(mp,
 510                                                 tp, bbno + j, minlen, maxlen,
 511                                                 len, &n, rbpp, rsb, prod, &r);
 512                                         if (error) {
 513                                                 return error;
 514                                         }
 515                                         /*
 516                                          * If it works, return the extent.
 517                                          */
 518                                         if (r != NULLRTBLOCK) {
 519                                                 *rtblock = r;
 520                                                 return 0;
 521                                         }
 522                                 }
 523                                 /*
 524                                  * There weren't intervening bitmap blocks
 525                                  * with a long enough extent, or the
 526                                  * allocation didn't work for some reason
 527                                  * (i.e. it's a little * too short).
 528                                  * Try to allocate from the summary block
 529                                  * that we found.
 530                                  */
 531                                 error = xfs_rtallocate_extent_block(mp, tp,
 532                                         bbno + i, minlen, maxlen, len, &n, rbpp,
 533                                         rsb, prod, &r);
 534                                 if (error) {
 535                                         return error;
 536                                 }
 537                                 /*
 538                                  * If it works, return the extent.
 539                                  */
 540                                 if (r != NULLRTBLOCK) {
 541                                         *rtblock = r;
 542                                         return 0;
 543                                 }
 544                         }
 545                 }
 546                 /*
 547                  * Loop control.  If we were on the positive side, and there's
 548                  * still more blocks on the negative side, go there.
 549                  */
 550                 if (i > 0 && (int)bbno - i >= 0)
 551                         i = -i;
 552                 /*
 553                  * If positive, and no more negative, but there are more
 554                  * positive, go there.
 555                  */
 556                 else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
 557                         i++;
 558                 /*
 559                  * If negative or 0 (just started), and there are positive
 560                  * blocks to go, go there.  The 0 case moves to block 1.
 561                  */
 562                 else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
 563                         i = 1 - i;
 564                 /*
 565                  * If negative or 0 and there are more negative blocks,
 566                  * go there.
 567                  */
 568                 else if (i <= 0 && (int)bbno + i > 0)
 569                         i--;
 570                 /*
 571                  * Must be done.  Return failure.
 572                  */
 573                 else
 574                         break;
 575         }
 576         *rtblock = NULLRTBLOCK;
 577         return 0;
 578 }
 579
 580 /*
 581  * Allocate an extent of length minlen<=len<=maxlen, with no position
 582  * specified.  If we don't get maxlen then use prod to trim
 583  * the length, if given.  The lengths are all in rtextents.
 584  */
 585 STATIC int                              /* error */
 586 xfs_rtallocate_extent_size(
 587         xfs_mount_t     *mp,            /* file system mount point */
 588         xfs_trans_t     *tp,            /* transaction pointer */
 589         xfs_extlen_t    minlen,         /* minimum length to allocate */
 590         xfs_extlen_t    maxlen,         /* maximum length to allocate */
 591         xfs_extlen_t    *len,           /* out: actual length allocated */
 592         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 593         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 594         xfs_extlen_t    prod,           /* extent product factor */
 595         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
 596 {
 597         int             error;          /* error value */
 598         int             i;              /* bitmap block number */
 599         int             l;              /* level number (loop control) */
 600         xfs_rtblock_t   n;              /* next block to be tried */
 601         xfs_rtblock_t   r;              /* result block number */
 602         xfs_suminfo_t   sum;            /* summary information for extents */
 603
 604         ASSERT(minlen % prod == 0 && maxlen % prod == 0);
 605         ASSERT(maxlen != 0);
 606
 607         /*
 608          * Loop over all the levels starting with maxlen.
 609          * At each level, look at all the bitmap blocks, to see if there
 610          * are extents starting there that are long enough (>= maxlen).
 611          * Note, only on the initial level can the allocation fail if
 612          * the summary says there's an extent.
 613          */
 614         for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) {
 615                 /*
 616                  * Loop over all the bitmap blocks.
 617                  */
 618                 for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
 619                         /*
 620                          * Get the summary for this level/block.
 621                          */
 622                         error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
 623                                 &sum);
 624                         if (error) {
 625                                 return error;
 626                         }
 627                         /*
 628                          * Nothing there, on to the next block.
 629                          */
 630                         if (!sum)
 631                                 continue;
 632                         /*
 633                          * Try allocating the extent.
 634                          */
 635                         error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
 636                                 maxlen, len, &n, rbpp, rsb, prod, &r);
 637                         if (error) {
 638                                 return error;
 639                         }
 640                         /*
 641                          * If it worked, return that.
 642                          */
 643                         if (r != NULLRTBLOCK) {
 644                                 *rtblock = r;
 645                                 return 0;
 646                         }
 647                         /*
 648                          * If the "next block to try" returned from the
 649                          * allocator is beyond the next bitmap block,
 650                          * skip to that bitmap block.
 651                          */
 652                         if (XFS_BITTOBLOCK(mp, n) > i + 1)
 653                                 i = XFS_BITTOBLOCK(mp, n) - 1;
 654                 }
 655         }
 656         /*
 657          * Didn't find any maxlen blocks.  Try smaller ones, unless
 658          * we're asking for a fixed size extent.
 659          */
 660         if (minlen > --maxlen) {
 661                 *rtblock = NULLRTBLOCK;
 662                 return 0;
 663         }
 664         ASSERT(minlen != 0);
 665         ASSERT(maxlen != 0);
 666
 667         /*
 668          * Loop over sizes, from maxlen down to minlen.
 669          * This time, when we do the allocations, allow smaller ones
 670          * to succeed.
 671          */
 672         for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
 673                 /*
 674                  * Loop over all the bitmap blocks, try an allocation
 675                  * starting in that block.
 676                  */
 677                 for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
 678                         /*
 679                          * Get the summary information for this level/block.
 680                          */
 681                         error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
 682                                                   &sum);
 683                         if (error) {
 684                                 return error;
 685                         }
 686                         /*
 687                          * If nothing there, go on to next.
 688                          */
 689                         if (!sum)
 690                                 continue;
 691                         /*
 692                          * Try the allocation.  Make sure the specified
 693                          * minlen/maxlen are in the possible range for
 694                          * this summary level.
 695                          */
 696                         error = xfs_rtallocate_extent_block(mp, tp, i,
 697                                         XFS_RTMAX(minlen, 1 << l),
 698                                         XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
 699                                         len, &n, rbpp, rsb, prod, &r);
 700                         if (error) {
 701                                 return error;
 702                         }
 703                         /*
 704                          * If it worked, return that extent.
 705                          */
 706                         if (r != NULLRTBLOCK) {
 707                                 *rtblock = r;
 708                                 return 0;
 709                         }
 710                         /*
 711                          * If the "next block to try" returned from the
 712                          * allocator is beyond the next bitmap block,
 713                          * skip to that bitmap block.
 714                          */
 715                         if (XFS_BITTOBLOCK(mp, n) > i + 1)
 716                                 i = XFS_BITTOBLOCK(mp, n) - 1;
 717                 }
 718         }
 719         /*
 720          * Got nothing, return failure.
 721          */
 722         *rtblock = NULLRTBLOCK;
 723         return 0;
 724 }
 725
 726 /*
 727  * Mark an extent specified by start and len allocated.
 728  * Updates all the summary information as well as the bitmap.
 729  */
 730 STATIC int                              /* error */
 731 xfs_rtallocate_range(
 732         xfs_mount_t     *mp,            /* file system mount point */
 733         xfs_trans_t     *tp,            /* transaction pointer */
 734         xfs_rtblock_t   start,          /* start block to allocate */
 735         xfs_extlen_t    len,            /* length to allocate */
 736         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 737         xfs_fsblock_t   *rsb)           /* in/out: summary block number */
 738 {
 739         xfs_rtblock_t   end;            /* end of the allocated extent */
 740         int             error;          /* error value */
 741         xfs_rtblock_t   postblock;      /* first block allocated > end */
 742         xfs_rtblock_t   preblock;       /* first block allocated < start */
 743
 744         end = start + len - 1;
 745         /*
 746          * Assume we're allocating out of the middle of a free extent.
 747          * We need to find the beginning and end of the extent so we can
 748          * properly update the summary.
 749          */
 750         error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
 751         if (error) {
 752                 return error;
 753         }
 754         /*
 755          * Find the next allocated block (end of free extent).
 756          */
 757         error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
 758                 &postblock);
 759         if (error) {
 760                 return error;
 761         }
 762         /*
 763          * Decrement the summary information corresponding to the entire
 764          * (old) free extent.
 765          */
 766         error = xfs_rtmodify_summary(mp, tp,
 767                 XFS_RTBLOCKLOG(postblock + 1 - preblock),
 768                 XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
 769         if (error) {
 770                 return error;
 771         }
 772         /*
 773          * If there are blocks not being allocated at the front of the
 774          * old extent, add summary data for them to be free.
 775          */
 776         if (preblock < start) {
 777                 error = xfs_rtmodify_summary(mp, tp,
 778                         XFS_RTBLOCKLOG(start - preblock),
 779                         XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
 780                 if (error) {
 781                         return error;
 782                 }
 783         }
 784         /*
 785          * If there are blocks not being allocated at the end of the
 786          * old extent, add summary data for them to be free.
 787          */
 788         if (postblock > end) {
 789                 error = xfs_rtmodify_summary(mp, tp,
 790                         XFS_RTBLOCKLOG(postblock - end),
 791                         XFS_BITTOBLOCK(mp, end + 1), 1, rbpp, rsb);
 792                 if (error) {
 793                         return error;
 794                 }
 795         }
 796         /*
 797          * Modify the bitmap to mark this extent allocated.
 798          */
 799         error = xfs_rtmodify_range(mp, tp, start, len, 0);
 800         return error;
 801 }
 802
 803 /*
 804  * Return whether there are any free extents in the size range given
 805  * by low and high, for the bitmap block bbno.
 806  */
 807 STATIC int                              /* error */
 808 xfs_rtany_summary(
 809         xfs_mount_t     *mp,            /* file system mount structure */
 810         xfs_trans_t     *tp,            /* transaction pointer */
 811         int             low,            /* low log2 extent size */
 812         int             high,           /* high log2 extent size */
 813         xfs_rtblock_t   bbno,           /* bitmap block number */
 814         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
 815         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
 816         int             *stat)          /* out: any good extents here? */
 817 {
 818         int             error;          /* error value */
 819         int             log;            /* loop counter, log2 of ext. size */
 820         xfs_suminfo_t   sum;            /* summary data */
 821
 822         /*
 823          * Loop over logs of extent sizes.  Order is irrelevant.
 824          */
 825         for (log = low; log <= high; log++) {
 826                 /*
 827                  * Get one summary datum.
 828                  */
 829                 error = xfs_rtget_summary(mp, tp, log, bbno, rbpp, rsb, &sum);
 830                 if (error) {
 831                         return error;
 832                 }
 833                 /*
 834                  * If there are any, return success.
 835                  */
 836                 if (sum) {
 837                         *stat = 1;
 838                         return 0;
 839                 }
 840         }
 841         /*
 842          * Found nothing, return failure.
 843          */
 844         *stat = 0;
 845         return 0;
 846 }
 847
 848 /*
 849  * Get a buffer for the bitmap or summary file block specified.
 850  * The buffer is returned read and locked.
 851  */
 852 STATIC int                              /* error */
 853 xfs_rtbuf_get(
 854         xfs_mount_t     *mp,            /* file system mount structure */
 855         xfs_trans_t     *tp,            /* transaction pointer */
 856         xfs_rtblock_t   block,          /* block number in bitmap or summary */
 857         int             issum,          /* is summary not bitmap */
 858         xfs_buf_t       **bpp)          /* output: buffer for the block */
 859 {
 860         xfs_buf_t       *bp;            /* block buffer, result */
 861         xfs_daddr_t     d;              /* disk addr of block */
 862         int             error;          /* error value */
 863         xfs_fsblock_t   fsb;            /* fs block number for block */
 864         xfs_inode_t     *ip;            /* bitmap or summary inode */
 865
 866         ip = issum ? mp->m_rsumip : mp->m_rbmip;
 867         /*
 868          * Map from the file offset (block) and inode number to the
 869          * file system block.
 870          */
 871         error = xfs_bmapi_single(tp, ip, XFS_DATA_FORK, &fsb, block);
 872         if (error) {
 873                 return error;
 874         }
 875         ASSERT(fsb != NULLFSBLOCK);
 876         /*
 877          * Convert to disk address for buffer cache.
 878          */
 879         d = XFS_FSB_TO_DADDR(mp, fsb);
 880         /*
 881          * Read the buffer.
 882          */
 883         error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
 884                                    mp->m_bsize, 0, &bp);
 885         if (error) {
 886                 return error;
 887         }
 888         ASSERT(bp && !XFS_BUF_GETERROR(bp));
 889         *bpp = bp;
 890         return 0;
 891 }
 892
 893 #ifdef DEBUG
 894 /*
 895  * Check that the given extent (block range) is allocated already.
 896  */
 897 STATIC int                              /* error */
 898 xfs_rtcheck_alloc_range(
 899         xfs_mount_t     *mp,            /* file system mount point */
 900         xfs_trans_t     *tp,            /* transaction pointer */
 901         xfs_rtblock_t   bno,            /* starting block number of extent */
 902         xfs_extlen_t    len,            /* length of extent */
 903         int             *stat)          /* out: 1 for allocated, 0 for not */
 904 {
 905         xfs_rtblock_t   new;            /* dummy for xfs_rtcheck_range */
 906
 907         return xfs_rtcheck_range(mp, tp, bno, len, 0, &new, stat);
 908 }
 909 #endif
 910
 911 /*
 912  * Check that the given range is either all allocated (val = 0) or
 913  * all free (val = 1).
 914  */
 915 STATIC int                              /* error */
 916 xfs_rtcheck_range(
 917         xfs_mount_t     *mp,            /* file system mount point */
 918         xfs_trans_t     *tp,            /* transaction pointer */
 919         xfs_rtblock_t   start,          /* starting block number of extent */
 920         xfs_extlen_t    len,            /* length of extent */
 921         int             val,            /* 1 for free, 0 for allocated */
 922         xfs_rtblock_t   *new,           /* out: first block not matching */
 923         int             *stat)          /* out: 1 for matches, 0 for not */
 924 {
 925         xfs_rtword_t    *b;             /* current word in buffer */
 926         int             bit;            /* bit number in the word */
 927         xfs_rtblock_t   block;          /* bitmap block number */
 928         xfs_buf_t       *bp;            /* buf for the block */
 929         xfs_rtword_t    *bufp;          /* starting word in buffer */
 930         int             error;          /* error value */
 931         xfs_rtblock_t   i;              /* current bit number rel. to start */
 932         xfs_rtblock_t   lastbit;        /* last useful bit in word */
 933         xfs_rtword_t    mask;           /* mask of relevant bits for value */
 934         xfs_rtword_t    wdiff;          /* difference from wanted value */
 935         int             word;           /* word number in the buffer */
 936
 937         /*
 938          * Compute starting bitmap block number
 939          */
 940         block = XFS_BITTOBLOCK(mp, start);
 941         /*
 942          * Read the bitmap block.
 943          */
 944         error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
 945         if (error) {
 946                 return error;
 947         }
 948         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
 949         /*
 950          * Compute the starting word's address, and starting bit.
 951          */
 952         word = XFS_BITTOWORD(mp, start);
 953         b = &bufp[word];
 954         bit = (int)(start & (XFS_NBWORD - 1));
 955         /*
 956          * 0 (allocated) => all zero's; 1 (free) => all one's.
 957          */
 958         val = -val;
 959         /*
 960          * If not starting on a word boundary, deal with the first
 961          * (partial) word.
 962          */
 963         if (bit) {
 964                 /*
 965                  * Compute first bit not examined.
 966                  */
 967                 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
 968                 /*
 969                  * Mask of relevant bits.
 970                  */
 971                 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
 972                 /*
 973                  * Compute difference between actual and desired value.
 974                  */
 975                 if ((wdiff = (*b ^ val) & mask)) {
 976                         /*
 977                          * Different, compute first wrong bit and return.
 978                          */
 979                         xfs_trans_brelse(tp, bp);
 980                         i = XFS_RTLOBIT(wdiff) - bit;
 981                         *new = start + i;
 982                         *stat = 0;
 983                         return 0;
 984                 }
 985                 i = lastbit - bit;
 986                 /*
 987                  * Go on to next block if that's where the next word is
 988                  * and we need the next word.
 989                  */
 990                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
 991                         /*
 992                          * If done with this block, get the next one.
 993                          */
 994                         xfs_trans_brelse(tp, bp);
 995                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
 996                         if (error) {
 997                                 return error;
 998                         }
 999                         b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1000                         word = 0;
1001                 } else {
1002                         /*
1003                          * Go on to the next word in the buffer.
1004                          */
1005                         b++;
1006                 }
1007         } else {
1008                 /*
1009                  * Starting on a word boundary, no partial word.
1010                  */
1011                 i = 0;
1012         }
1013         /*
1014          * Loop over whole words in buffers.  When we use up one buffer
1015          * we move on to the next one.
1016          */
1017         while (len - i >= XFS_NBWORD) {
1018                 /*
1019                  * Compute difference between actual and desired value.
1020                  */
1021                 if ((wdiff = *b ^ val)) {
1022                         /*
1023                          * Different, compute first wrong bit and return.
1024                          */
1025                         xfs_trans_brelse(tp, bp);
1026                         i += XFS_RTLOBIT(wdiff);
1027                         *new = start + i;
1028                         *stat = 0;
1029                         return 0;
1030                 }
1031                 i += XFS_NBWORD;
1032                 /*
1033                  * Go on to next block if that's where the next word is
1034                  * and we need the next word.
1035                  */
1036                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1037                         /*
1038                          * If done with this block, get the next one.
1039                          */
1040                         xfs_trans_brelse(tp, bp);
1041                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1042                         if (error) {
1043                                 return error;
1044                         }
1045                         b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1046                         word = 0;
1047                 } else {
1048                         /*
1049                          * Go on to the next word in the buffer.
1050                          */
1051                         b++;
1052                 }
1053         }
1054         /*
1055          * If not ending on a word boundary, deal with the last
1056          * (partial) word.
1057          */
1058         if ((lastbit = len - i)) {
1059                 /*
1060                  * Mask of relevant bits.
1061                  */
1062                 mask = ((xfs_rtword_t)1 << lastbit) - 1;
1063                 /*
1064                  * Compute difference between actual and desired value.
1065                  */
1066                 if ((wdiff = (*b ^ val) & mask)) {
1067                         /*
1068                          * Different, compute first wrong bit and return.
1069                          */
1070                         xfs_trans_brelse(tp, bp);
1071                         i += XFS_RTLOBIT(wdiff);
1072                         *new = start + i;
1073                         *stat = 0;
1074                         return 0;
1075                 } else
1076                         i = len;
1077         }
1078         /*
1079          * Successful, return.
1080          */
1081         xfs_trans_brelse(tp, bp);
1082         *new = start + i;
1083         *stat = 1;
1084         return 0;
1085 }
1086
1087 /*
1088  * Copy and transform the summary file, given the old and new
1089  * parameters in the mount structures.
1090  */
1091 STATIC int                              /* error */
1092 xfs_rtcopy_summary(
1093         xfs_mount_t     *omp,           /* old file system mount point */
1094         xfs_mount_t     *nmp,           /* new file system mount point */
1095         xfs_trans_t     *tp)            /* transaction pointer */
1096 {
1097         xfs_rtblock_t   bbno;           /* bitmap block number */
1098         xfs_buf_t       *bp;            /* summary buffer */
1099         int             error;          /* error return value */
1100         int             log;            /* summary level number (log length) */
1101         xfs_suminfo_t   sum;            /* summary data */
1102         xfs_fsblock_t   sumbno;         /* summary block number */
1103
1104         bp = NULL;
1105         for (log = omp->m_rsumlevels - 1; log >= 0; log--) {
1106                 for (bbno = omp->m_sb.sb_rbmblocks - 1;
1107                      (xfs_srtblock_t)bbno >= 0;
1108                      bbno--) {
1109                         error = xfs_rtget_summary(omp, tp, log, bbno, &bp,
1110                                 &sumbno, &sum);
1111                         if (error)
1112                                 return error;
1113                         if (sum == 0)
1114                                 continue;
1115                         error = xfs_rtmodify_summary(omp, tp, log, bbno, -sum,
1116                                 &bp, &sumbno);
1117                         if (error)
1118                                 return error;
1119                         error = xfs_rtmodify_summary(nmp, tp, log, bbno, sum,
1120                                 &bp, &sumbno);
1121                         if (error)
1122                                 return error;
1123                         ASSERT(sum > 0);
1124                 }
1125         }
1126         return 0;
1127 }
1128
1129 /*
1130  * Searching backward from start to limit, find the first block whose
1131  * allocated/free state is different from start's.
1132  */
1133 STATIC int                              /* error */
1134 xfs_rtfind_back(
1135         xfs_mount_t     *mp,            /* file system mount point */
1136         xfs_trans_t     *tp,            /* transaction pointer */
1137         xfs_rtblock_t   start,          /* starting block to look at */
1138         xfs_rtblock_t   limit,          /* last block to look at */
1139         xfs_rtblock_t   *rtblock)       /* out: start block found */
1140 {
1141         xfs_rtword_t    *b;             /* current word in buffer */
1142         int             bit;            /* bit number in the word */
1143         xfs_rtblock_t   block;          /* bitmap block number */
1144         xfs_buf_t       *bp;            /* buf for the block */
1145         xfs_rtword_t    *bufp;          /* starting word in buffer */
1146         int             error;          /* error value */
1147         xfs_rtblock_t   firstbit;       /* first useful bit in the word */
1148         xfs_rtblock_t   i;              /* current bit number rel. to start */
1149         xfs_rtblock_t   len;            /* length of inspected area */
1150         xfs_rtword_t    mask;           /* mask of relevant bits for value */
1151         xfs_rtword_t    want;           /* mask for "good" values */
1152         xfs_rtword_t    wdiff;          /* difference from wanted value */
1153         int             word;           /* word number in the buffer */
1154
1155         /*
1156          * Compute and read in starting bitmap block for starting block.
1157          */
1158         block = XFS_BITTOBLOCK(mp, start);
1159         error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1160         if (error) {
1161                 return error;
1162         }
1163         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1164         /*
1165          * Get the first word's index & point to it.
1166          */
1167         word = XFS_BITTOWORD(mp, start);
1168         b = &bufp[word];
1169         bit = (int)(start & (XFS_NBWORD - 1));
1170         len = start - limit + 1;
1171         /*
1172          * Compute match value, based on the bit at start: if 1 (free)
1173          * then all-ones, else all-zeroes.
1174          */
1175         want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
1176         /*
1177          * If the starting position is not word-aligned, deal with the
1178          * partial word.
1179          */
1180         if (bit < XFS_NBWORD - 1) {
1181                 /*
1182                  * Calculate first (leftmost) bit number to look at,
1183                  * and mask for all the relevant bits in this word.
1184                  */
1185                 firstbit = XFS_RTMAX((xfs_srtblock_t)(bit - len + 1), 0);
1186                 mask = (((xfs_rtword_t)1 << (bit - firstbit + 1)) - 1) <<
1187                         firstbit;
1188                 /*
1189                  * Calculate the difference between the value there
1190                  * and what we're looking for.
1191                  */
1192                 if ((wdiff = (*b ^ want) & mask)) {
1193                         /*
1194                          * Different.  Mark where we are and return.
1195                          */
1196                         xfs_trans_brelse(tp, bp);
1197                         i = bit - XFS_RTHIBIT(wdiff);
1198                         *rtblock = start - i + 1;
1199                         return 0;
1200                 }
1201                 i = bit - firstbit + 1;
1202                 /*
1203                  * Go on to previous block if that's where the previous word is
1204                  * and we need the previous word.
1205                  */
1206                 if (--word == -1 && i < len) {
1207                         /*
1208                          * If done with this block, get the previous one.
1209                          */
1210                         xfs_trans_brelse(tp, bp);
1211                         error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
1212                         if (error) {
1213                                 return error;
1214                         }
1215                         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1216                         word = XFS_BLOCKWMASK(mp);
1217                         b = &bufp[word];
1218                 } else {
1219                         /*
1220                          * Go on to the previous word in the buffer.
1221                          */
1222                         b--;
1223                 }
1224         } else {
1225                 /*
1226                  * Starting on a word boundary, no partial word.
1227                  */
1228                 i = 0;
1229         }
1230         /*
1231          * Loop over whole words in buffers.  When we use up one buffer
1232          * we move on to the previous one.
1233          */
1234         while (len - i >= XFS_NBWORD) {
1235                 /*
1236                  * Compute difference between actual and desired value.
1237                  */
1238                 if ((wdiff = *b ^ want)) {
1239                         /*
1240                          * Different, mark where we are and return.
1241                          */
1242                         xfs_trans_brelse(tp, bp);
1243                         i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
1244                         *rtblock = start - i + 1;
1245                         return 0;
1246                 }
1247                 i += XFS_NBWORD;
1248                 /*
1249                  * Go on to previous block if that's where the previous word is
1250                  * and we need the previous word.
1251                  */
1252                 if (--word == -1 && i < len) {
1253                         /*
1254                          * If done with this block, get the previous one.
1255                          */
1256                         xfs_trans_brelse(tp, bp);
1257                         error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
1258                         if (error) {
1259                                 return error;
1260                         }
1261                         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1262                         word = XFS_BLOCKWMASK(mp);
1263                         b = &bufp[word];
1264                 } else {
1265                         /*
1266                          * Go on to the previous word in the buffer.
1267                          */
1268                         b--;
1269                 }
1270         }
1271         /*
1272          * If not ending on a word boundary, deal with the last
1273          * (partial) word.
1274          */
1275         if (len - i) {
1276                 /*
1277                  * Calculate first (leftmost) bit number to look at,
1278                  * and mask for all the relevant bits in this word.
1279                  */
1280                 firstbit = XFS_NBWORD - (len - i);
1281                 mask = (((xfs_rtword_t)1 << (len - i)) - 1) << firstbit;
1282                 /*
1283                  * Compute difference between actual and desired value.
1284                  */
1285                 if ((wdiff = (*b ^ want) & mask)) {
1286                         /*
1287                          * Different, mark where we are and return.
1288                          */
1289                         xfs_trans_brelse(tp, bp);
1290                         i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
1291                         *rtblock = start - i + 1;
1292                         return 0;
1293                 } else
1294                         i = len;
1295         }
1296         /*
1297          * No match, return that we scanned the whole area.
1298          */
1299         xfs_trans_brelse(tp, bp);
1300         *rtblock = start - i + 1;
1301         return 0;
1302 }
1303
1304 /*
1305  * Searching forward from start to limit, find the first block whose
1306  * allocated/free state is different from start's.
1307  */
1308 STATIC int                              /* error */
1309 xfs_rtfind_forw(
1310         xfs_mount_t     *mp,            /* file system mount point */
1311         xfs_trans_t     *tp,            /* transaction pointer */
1312         xfs_rtblock_t   start,          /* starting block to look at */
1313         xfs_rtblock_t   limit,          /* last block to look at */
1314         xfs_rtblock_t   *rtblock)       /* out: start block found */
1315 {
1316         xfs_rtword_t    *b;             /* current word in buffer */
1317         int             bit;            /* bit number in the word */
1318         xfs_rtblock_t   block;          /* bitmap block number */
1319         xfs_buf_t       *bp;            /* buf for the block */
1320         xfs_rtword_t    *bufp;          /* starting word in buffer */
1321         int             error;          /* error value */
1322         xfs_rtblock_t   i;              /* current bit number rel. to start */
1323         xfs_rtblock_t   lastbit;        /* last useful bit in the word */
1324         xfs_rtblock_t   len;            /* length of inspected area */
1325         xfs_rtword_t    mask;           /* mask of relevant bits for value */
1326         xfs_rtword_t    want;           /* mask for "good" values */
1327         xfs_rtword_t    wdiff;          /* difference from wanted value */
1328         int             word;           /* word number in the buffer */
1329
1330         /*
1331          * Compute and read in starting bitmap block for starting block.
1332          */
1333         block = XFS_BITTOBLOCK(mp, start);
1334         error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1335         if (error) {
1336                 return error;
1337         }
1338         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1339         /*
1340          * Get the first word's index & point to it.
1341          */
1342         word = XFS_BITTOWORD(mp, start);
1343         b = &bufp[word];
1344         bit = (int)(start & (XFS_NBWORD - 1));
1345         len = limit - start + 1;
1346         /*
1347          * Compute match value, based on the bit at start: if 1 (free)
1348          * then all-ones, else all-zeroes.
1349          */
1350         want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
1351         /*
1352          * If the starting position is not word-aligned, deal with the
1353          * partial word.
1354          */
1355         if (bit) {
1356                 /*
1357                  * Calculate last (rightmost) bit number to look at,
1358                  * and mask for all the relevant bits in this word.
1359                  */
1360                 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
1361                 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
1362                 /*
1363                  * Calculate the difference between the value there
1364                  * and what we're looking for.
1365                  */
1366                 if ((wdiff = (*b ^ want) & mask)) {
1367                         /*
1368                          * Different.  Mark where we are and return.
1369                          */
1370                         xfs_trans_brelse(tp, bp);
1371                         i = XFS_RTLOBIT(wdiff) - bit;
1372                         *rtblock = start + i - 1;
1373                         return 0;
1374                 }
1375                 i = lastbit - bit;
1376                 /*
1377                  * Go on to next block if that's where the next word is
1378                  * and we need the next word.
1379                  */
1380                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1381                         /*
1382                          * If done with this block, get the previous one.
1383                          */
1384                         xfs_trans_brelse(tp, bp);
1385                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1386                         if (error) {
1387                                 return error;
1388                         }
1389                         b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1390                         word = 0;
1391                 } else {
1392                         /*
1393                          * Go on to the previous word in the buffer.
1394                          */
1395                         b++;
1396                 }
1397         } else {
1398                 /*
1399                  * Starting on a word boundary, no partial word.
1400                  */
1401                 i = 0;
1402         }
1403         /*
1404          * Loop over whole words in buffers.  When we use up one buffer
1405          * we move on to the next one.
1406          */
1407         while (len - i >= XFS_NBWORD) {
1408                 /*
1409                  * Compute difference between actual and desired value.
1410                  */
1411                 if ((wdiff = *b ^ want)) {
1412                         /*
1413                          * Different, mark where we are and return.
1414                          */
1415                         xfs_trans_brelse(tp, bp);
1416                         i += XFS_RTLOBIT(wdiff);
1417                         *rtblock = start + i - 1;
1418                         return 0;
1419                 }
1420                 i += XFS_NBWORD;
1421                 /*
1422                  * Go on to next block if that's where the next word is
1423                  * and we need the next word.
1424                  */
1425                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1426                         /*
1427                          * If done with this block, get the next one.
1428                          */
1429                         xfs_trans_brelse(tp, bp);
1430                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1431                         if (error) {
1432                                 return error;
1433                         }
1434                         b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1435                         word = 0;
1436                 } else {
1437                         /*
1438                          * Go on to the next word in the buffer.
1439                          */
1440                         b++;
1441                 }
1442         }
1443         /*
1444          * If not ending on a word boundary, deal with the last
1445          * (partial) word.
1446          */
1447         if ((lastbit = len - i)) {
1448                 /*
1449                  * Calculate mask for all the relevant bits in this word.
1450                  */
1451                 mask = ((xfs_rtword_t)1 << lastbit) - 1;
1452                 /*
1453                  * Compute difference between actual and desired value.
1454                  */
1455                 if ((wdiff = (*b ^ want) & mask)) {
1456                         /*
1457                          * Different, mark where we are and return.
1458                          */
1459                         xfs_trans_brelse(tp, bp);
1460                         i += XFS_RTLOBIT(wdiff);
1461                         *rtblock = start + i - 1;
1462                         return 0;
1463                 } else
1464                         i = len;
1465         }
1466         /*
1467          * No match, return that we scanned the whole area.
1468          */
1469         xfs_trans_brelse(tp, bp);
1470         *rtblock = start + i - 1;
1471         return 0;
1472 }
1473
1474 /*
1475  * Mark an extent specified by start and len freed.
1476  * Updates all the summary information as well as the bitmap.
1477  */
1478 STATIC int                              /* error */
1479 xfs_rtfree_range(
1480         xfs_mount_t     *mp,            /* file system mount point */
1481         xfs_trans_t     *tp,            /* transaction pointer */
1482         xfs_rtblock_t   start,          /* starting block to free */
1483         xfs_extlen_t    len,            /* length to free */
1484         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
1485         xfs_fsblock_t   *rsb)           /* in/out: summary block number */
1486 {
1487         xfs_rtblock_t   end;            /* end of the freed extent */
1488         int             error;          /* error value */
1489         xfs_rtblock_t   postblock;      /* first block freed > end */
1490         xfs_rtblock_t   preblock;       /* first block freed < start */
1491
1492         end = start + len - 1;
1493         /*
1494          * Modify the bitmap to mark this extent freed.
1495          */
1496         error = xfs_rtmodify_range(mp, tp, start, len, 1);
1497         if (error) {
1498                 return error;
1499         }
1500         /*
1501          * Assume we're freeing out of the middle of an allocated extent.
1502          * We need to find the beginning and end of the extent so we can
1503          * properly update the summary.
1504          */
1505         error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
1506         if (error) {
1507                 return error;
1508         }
1509         /*
1510          * Find the next allocated block (end of allocated extent).
1511          */
1512         error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
1513                 &postblock);
1514         if (error)
1515                 return error;
1516         /*
1517          * If there are blocks not being freed at the front of the
1518          * old extent, add summary data for them to be allocated.
1519          */
1520         if (preblock < start) {
1521                 error = xfs_rtmodify_summary(mp, tp,
1522                         XFS_RTBLOCKLOG(start - preblock),
1523                         XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
1524                 if (error) {
1525                         return error;
1526                 }
1527         }
1528         /*
1529          * If there are blocks not being freed at the end of the
1530          * old extent, add summary data for them to be allocated.
1531          */
1532         if (postblock > end) {
1533                 error = xfs_rtmodify_summary(mp, tp,
1534                         XFS_RTBLOCKLOG(postblock - end),
1535                         XFS_BITTOBLOCK(mp, end + 1), -1, rbpp, rsb);
1536                 if (error) {
1537                         return error;
1538                 }
1539         }
1540         /*
1541          * Increment the summary information corresponding to the entire
1542          * (new) free extent.
1543          */
1544         error = xfs_rtmodify_summary(mp, tp,
1545                 XFS_RTBLOCKLOG(postblock + 1 - preblock),
1546                 XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
1547         return error;
1548 }
1549
1550 /*
1551  * Read and return the summary information for a given extent size,
1552  * bitmap block combination.
1553  * Keeps track of a current summary block, so we don't keep reading
1554  * it from the buffer cache.
1555  */
1556 STATIC int                              /* error */
1557 xfs_rtget_summary(
1558         xfs_mount_t     *mp,            /* file system mount structure */
1559         xfs_trans_t     *tp,            /* transaction pointer */
1560         int             log,            /* log2 of extent size */
1561         xfs_rtblock_t   bbno,           /* bitmap block number */
1562         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
1563         xfs_fsblock_t   *rsb,           /* in/out: summary block number */
1564         xfs_suminfo_t   *sum)           /* out: summary info for this block */
1565 {
1566         xfs_buf_t       *bp;            /* buffer for summary block */
1567         int             error;          /* error value */
1568         xfs_fsblock_t   sb;             /* summary fsblock */
1569         int             so;             /* index into the summary file */
1570         xfs_suminfo_t   *sp;            /* pointer to returned data */
1571
1572         /*
1573          * Compute entry number in the summary file.
1574          */
1575         so = XFS_SUMOFFS(mp, log, bbno);
1576         /*
1577          * Compute the block number in the summary file.
1578          */
1579         sb = XFS_SUMOFFSTOBLOCK(mp, so);
1580         /*
1581          * If we have an old buffer, and the block number matches, use that.
1582          */
1583         if (rbpp && *rbpp && *rsb == sb)
1584                 bp = *rbpp;
1585         /*
1586          * Otherwise we have to get the buffer.
1587          */
1588         else {
1589                 /*
1590                  * If there was an old one, get rid of it first.
1591                  */
1592                 if (rbpp && *rbpp)
1593                         xfs_trans_brelse(tp, *rbpp);
1594                 error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
1595                 if (error) {
1596                         return error;
1597                 }
1598                 /*
1599                  * Remember this buffer and block for the next call.
1600                  */
1601                 if (rbpp) {
1602                         *rbpp = bp;
1603                         *rsb = sb;
1604                 }
1605         }
1606         /*
1607          * Point to the summary information & copy it out.
1608          */
1609         sp = XFS_SUMPTR(mp, bp, so);
1610         *sum = *sp;
1611         /*
1612          * Drop the buffer if we're not asked to remember it.
1613          */
1614         if (!rbpp)
1615                 xfs_trans_brelse(tp, bp);
1616         return 0;
1617 }
1618
1619 /*
1620  * Set the given range of bitmap bits to the given value.
1621  * Do whatever I/O and logging is required.
1622  */
1623 STATIC int                              /* error */
1624 xfs_rtmodify_range(
1625         xfs_mount_t     *mp,            /* file system mount point */
1626         xfs_trans_t     *tp,            /* transaction pointer */
1627         xfs_rtblock_t   start,          /* starting block to modify */
1628         xfs_extlen_t    len,            /* length of extent to modify */
1629         int             val)            /* 1 for free, 0 for allocated */
1630 {
1631         xfs_rtword_t    *b;             /* current word in buffer */
1632         int             bit;            /* bit number in the word */
1633         xfs_rtblock_t   block;          /* bitmap block number */
1634         xfs_buf_t       *bp;            /* buf for the block */
1635         xfs_rtword_t    *bufp;          /* starting word in buffer */
1636         int             error;          /* error value */
1637         xfs_rtword_t    *first;         /* first used word in the buffer */
1638         int             i;              /* current bit number rel. to start */
1639         int             lastbit;        /* last useful bit in word */
1640         xfs_rtword_t    mask;           /* mask o frelevant bits for value */
1641         int             word;           /* word number in the buffer */
1642
1643         /*
1644          * Compute starting bitmap block number.
1645          */
1646         block = XFS_BITTOBLOCK(mp, start);
1647         /*
1648          * Read the bitmap block, and point to its data.
1649          */
1650         error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
1651         if (error) {
1652                 return error;
1653         }
1654         bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1655         /*
1656          * Compute the starting word's address, and starting bit.
1657          */
1658         word = XFS_BITTOWORD(mp, start);
1659         first = b = &bufp[word];
1660         bit = (int)(start & (XFS_NBWORD - 1));
1661         /*
1662          * 0 (allocated) => all zeroes; 1 (free) => all ones.
1663          */
1664         val = -val;
1665         /*
1666          * If not starting on a word boundary, deal with the first
1667          * (partial) word.
1668          */
1669         if (bit) {
1670                 /*
1671                  * Compute first bit not changed and mask of relevant bits.
1672                  */
1673                 lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
1674                 mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
1675                 /*
1676                  * Set/clear the active bits.
1677                  */
1678                 if (val)
1679                         *b |= mask;
1680                 else
1681                         *b &= ~mask;
1682                 i = lastbit - bit;
1683                 /*
1684                  * Go on to the next block if that's where the next word is
1685                  * and we need the next word.
1686                  */
1687                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1688                         /*
1689                          * Log the changed part of this block.
1690                          * Get the next one.
1691                          */
1692                         xfs_trans_log_buf(tp, bp,
1693                                 (uint)((char *)first - (char *)bufp),
1694                                 (uint)((char *)b - (char *)bufp));
1695                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1696                         if (error) {
1697                                 return error;
1698                         }
1699                         first = b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1700                         word = 0;
1701                 } else {
1702                         /*
1703                          * Go on to the next word in the buffer
1704                          */
1705                         b++;
1706                 }
1707         } else {
1708                 /*
1709                  * Starting on a word boundary, no partial word.
1710                  */
1711                 i = 0;
1712         }
1713         /*
1714          * Loop over whole words in buffers.  When we use up one buffer
1715          * we move on to the next one.
1716          */
1717         while (len - i >= XFS_NBWORD) {
1718                 /*
1719                  * Set the word value correctly.
1720                  */
1721                 *b = val;
1722                 i += XFS_NBWORD;
1723                 /*
1724                  * Go on to the next block if that's where the next word is
1725                  * and we need the next word.
1726                  */
1727                 if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
1728                         /*
1729                          * Log the changed part of this block.
1730                          * Get the next one.
1731                          */
1732                         xfs_trans_log_buf(tp, bp,
1733                                 (uint)((char *)first - (char *)bufp),
1734                                 (uint)((char *)b - (char *)bufp));
1735                         error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
1736                         if (error) {
1737                                 return error;
1738                         }
1739                         first = b = bufp = (xfs_rtword_t *)XFS_BUF_PTR(bp);
1740                         word = 0;
1741                 } else {
1742                         /*
1743                          * Go on to the next word in the buffer
1744                          */
1745                         b++;
1746                 }
1747         }
1748         /*
1749          * If not ending on a word boundary, deal with the last
1750          * (partial) word.
1751          */
1752         if ((lastbit = len - i)) {
1753                 /*
1754                  * Compute a mask of relevant bits.
1755                  */
1756                 bit = 0;
1757                 mask = ((xfs_rtword_t)1 << lastbit) - 1;
1758                 /*
1759                  * Set/clear the active bits.
1760                  */
1761                 if (val)
1762                         *b |= mask;
1763                 else
1764                         *b &= ~mask;
1765                 b++;
1766         }
1767         /*
1768          * Log any remaining changed bytes.
1769          */
1770         if (b > first)
1771                 xfs_trans_log_buf(tp, bp, (uint)((char *)first - (char *)bufp),
1772                         (uint)((char *)b - (char *)bufp - 1));
1773         return 0;
1774 }
1775
1776 /*
1777  * Read and modify the summary information for a given extent size,
1778  * bitmap block combination.
1779  * Keeps track of a current summary block, so we don't keep reading
1780  * it from the buffer cache.
1781  */
1782 STATIC int                              /* error */
1783 xfs_rtmodify_summary(
1784         xfs_mount_t     *mp,            /* file system mount point */
1785         xfs_trans_t     *tp,            /* transaction pointer */
1786         int             log,            /* log2 of extent size */
1787         xfs_rtblock_t   bbno,           /* bitmap block number */
1788         int             delta,          /* change to make to summary info */
1789         xfs_buf_t       **rbpp,         /* in/out: summary block buffer */
1790         xfs_fsblock_t   *rsb)           /* in/out: summary block number */
1791 {
1792         xfs_buf_t       *bp;            /* buffer for the summary block */
1793         int             error;          /* error value */
1794         xfs_fsblock_t   sb;             /* summary fsblock */
1795         int             so;             /* index into the summary file */
1796         xfs_suminfo_t   *sp;            /* pointer to returned data */
1797
1798         /*
1799          * Compute entry number in the summary file.
1800          */
1801         so = XFS_SUMOFFS(mp, log, bbno);
1802         /*
1803          * Compute the block number in the summary file.
1804          */
1805         sb = XFS_SUMOFFSTOBLOCK(mp, so);
1806         /*
1807          * If we have an old buffer, and the block number matches, use that.
1808          */
1809         if (rbpp && *rbpp && *rsb == sb)
1810                 bp = *rbpp;
1811         /*
1812          * Otherwise we have to get the buffer.
1813          */
1814         else {
1815                 /*
1816                  * If there was an old one, get rid of it first.
1817                  */
1818                 if (rbpp && *rbpp)
1819                         xfs_trans_brelse(tp, *rbpp);
1820                 error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
1821                 if (error) {
1822                         return error;
1823                 }
1824                 /*
1825                  * Remember this buffer and block for the next call.
1826                  */
1827                 if (rbpp) {
1828                         *rbpp = bp;
1829                         *rsb = sb;
1830                 }
1831         }
1832         /*
1833          * Point to the summary information, modify and log it.
1834          */
1835         sp = XFS_SUMPTR(mp, bp, so);
1836         *sp += delta;
1837         xfs_trans_log_buf(tp, bp, (uint)((char *)sp - (char *)XFS_BUF_PTR(bp)),
1838                 (uint)((char *)sp - (char *)XFS_BUF_PTR(bp) + sizeof(*sp) - 1));
1839         return 0;
1840 }
1841
1842 /*
1843  * Visible (exported) functions.
1844  */
1845
1846 /*
1847  * Grow the realtime area of the filesystem.
1848  */
1849 int
1850 xfs_growfs_rt(
1851         xfs_mount_t     *mp,            /* mount point for filesystem */
1852         xfs_growfs_rt_t *in)            /* growfs rt input struct */
1853 {
1854         xfs_rtblock_t   bmbno;          /* bitmap block number */
1855         xfs_buf_t       *bp;            /* temporary buffer */
1856         int             error;          /* error return value */
1857         xfs_inode_t     *ip;            /* bitmap inode, used as lock */
1858         xfs_mount_t     *nmp;           /* new (fake) mount structure */
1859         xfs_drfsbno_t   nrblocks;       /* new number of realtime blocks */
1860         xfs_extlen_t    nrbmblocks;     /* new number of rt bitmap blocks */
1861         xfs_drtbno_t    nrextents;      /* new number of realtime extents */
1862         uint8_t         nrextslog;      /* new log2 of sb_rextents */
1863         xfs_extlen_t    nrsumblocks;    /* new number of summary blocks */
1864         uint            nrsumlevels;    /* new rt summary levels */
1865         uint            nrsumsize;      /* new size of rt summary, bytes */
1866         xfs_sb_t        *nsbp;          /* new superblock */
1867         xfs_extlen_t    rbmblocks;      /* current number of rt bitmap blocks */
1868         xfs_extlen_t    rsumblocks;     /* current number of rt summary blks */
1869         xfs_sb_t        *sbp;           /* old superblock */
1870         xfs_fsblock_t   sumbno;         /* summary block number */
1871
1872         sbp = &mp->m_sb;
1873         /*
1874          * Initial error checking.
1875          */
1876         if (!capable(CAP_SYS_ADMIN))
1877                 return XFS_ERROR(EPERM);
1878         if (mp->m_rtdev_targp == NULL || mp->m_rbmip == NULL ||
1879             (nrblocks = in->newblocks) <= sbp->sb_rblocks ||
1880             (sbp->sb_rblocks && (in->extsize != sbp->sb_rextsize)))
1881                 return XFS_ERROR(EINVAL);
1882         if ((error = xfs_sb_validate_fsb_count(sbp, nrblocks)))
1883                 return error;
1884         /*
1885          * Read in the last block of the device, make sure it exists.
1886          */
1887         bp = xfs_buf_read_uncached(mp, mp->m_rtdev_targp,
1888                                 XFS_FSB_TO_BB(mp, nrblocks - 1),
1889                                 XFS_FSB_TO_B(mp, 1), 0);
1890         if (!bp)
1891                 return EIO;
1892         xfs_buf_relse(bp);
1893
1894         /*
1895          * Calculate new parameters.  These are the final values to be reached.
1896          */
1897         nrextents = nrblocks;
1898         do_div(nrextents, in->extsize);
1899         nrbmblocks = howmany_64(nrextents, NBBY * sbp->sb_blocksize);
1900         nrextslog = xfs_highbit32(nrextents);
1901         nrsumlevels = nrextslog + 1;
1902         nrsumsize = (uint)sizeof(xfs_suminfo_t) * nrsumlevels * nrbmblocks;
1903         nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1904         nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1905         /*
1906          * New summary size can't be more than half the size of
1907          * the log.  This prevents us from getting a log overflow,
1908          * since we'll log basically the whole summary file at once.
1909          */
1910         if (nrsumblocks > (mp->m_sb.sb_logblocks >> 1))
1911                 return XFS_ERROR(EINVAL);
1912         /*
1913          * Get the old block counts for bitmap and summary inodes.
1914          * These can't change since other growfs callers are locked out.
1915          */
1916         rbmblocks = XFS_B_TO_FSB(mp, mp->m_rbmip->i_d.di_size);
1917         rsumblocks = XFS_B_TO_FSB(mp, mp->m_rsumip->i_d.di_size);
1918         /*
1919          * Allocate space to the bitmap and summary files, as necessary.
1920          */
1921         if ((error = xfs_growfs_rt_alloc(mp, rbmblocks, nrbmblocks,
1922                         mp->m_sb.sb_rbmino)))
1923                 return error;
1924         if ((error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks,
1925                         mp->m_sb.sb_rsumino)))
1926                 return error;
1927         /*
1928          * Allocate a new (fake) mount/sb.
1929          */
1930         nmp = kmem_alloc(sizeof(*nmp), KM_SLEEP);
1931         /*
1932          * Loop over the bitmap blocks.
1933          * We will do everything one bitmap block at a time.
1934          * Skip the current block if it is exactly full.
1935          * This also deals with the case where there were no rtextents before.
1936          */
1937         for (bmbno = sbp->sb_rbmblocks -
1938                      ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
1939              bmbno < nrbmblocks;
1940              bmbno++) {
1941                 xfs_trans_t     *tp;
1942                 int             cancelflags = 0;
1943
1944                 *nmp = *mp;
1945                 nsbp = &nmp->m_sb;
1946                 /*
1947                  * Calculate new sb and mount fields for this round.
1948                  */
1949                 nsbp->sb_rextsize = in->extsize;
1950                 nsbp->sb_rbmblocks = bmbno + 1;
1951                 nsbp->sb_rblocks =
1952                         XFS_RTMIN(nrblocks,
1953                                   nsbp->sb_rbmblocks * NBBY *
1954                                   nsbp->sb_blocksize * nsbp->sb_rextsize);
1955                 nsbp->sb_rextents = nsbp->sb_rblocks;
1956                 do_div(nsbp->sb_rextents, nsbp->sb_rextsize);
1957                 ASSERT(nsbp->sb_rextents != 0);
1958                 nsbp->sb_rextslog = xfs_highbit32(nsbp->sb_rextents);
1959                 nrsumlevels = nmp->m_rsumlevels = nsbp->sb_rextslog + 1;
1960                 nrsumsize =
1961                         (uint)sizeof(xfs_suminfo_t) * nrsumlevels *
1962                         nsbp->sb_rbmblocks;
1963                 nrsumblocks = XFS_B_TO_FSB(mp, nrsumsize);
1964                 nmp->m_rsumsize = nrsumsize = XFS_FSB_TO_B(mp, nrsumblocks);
1965                 /*
1966                  * Start a transaction, get the log reservation.
1967                  */
1968                 tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFSRT_FREE);
1969                 if ((error = xfs_trans_reserve(tp, 0,
1970                                 XFS_GROWRTFREE_LOG_RES(nmp), 0, 0, 0)))
1971                         goto error_cancel;
1972                 /*
1973                  * Lock out other callers by grabbing the bitmap inode lock.
1974                  */
1975                 if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
1976                                                 XFS_ILOCK_EXCL, &ip)))
1977                         goto error_cancel;
1978                 ASSERT(ip == mp->m_rbmip);
1979                 /*
1980                  * Update the bitmap inode's size.
1981                  */
1982                 mp->m_rbmip->i_d.di_size =
1983                         nsbp->sb_rbmblocks * nsbp->sb_blocksize;
1984                 xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
1985                 cancelflags |= XFS_TRANS_ABORT;
1986                 /*
1987                  * Get the summary inode into the transaction.
1988                  */
1989                 if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rsumino, 0,
1990                                                 XFS_ILOCK_EXCL, &ip)))
1991                         goto error_cancel;
1992                 ASSERT(ip == mp->m_rsumip);
1993                 /*
1994                  * Update the summary inode's size.
1995                  */
1996                 mp->m_rsumip->i_d.di_size = nmp->m_rsumsize;
1997                 xfs_trans_log_inode(tp, mp->m_rsumip, XFS_ILOG_CORE);
1998                 /*
1999                  * Copy summary data from old to new sizes.
2000                  * Do this when the real size (not block-aligned) changes.
2001                  */
2002                 if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
2003                     mp->m_rsumlevels != nmp->m_rsumlevels) {
2004                         error = xfs_rtcopy_summary(mp, nmp, tp);
2005                         if (error)
2006                                 goto error_cancel;
2007                 }
2008                 /*
2009                  * Update superblock fields.
2010                  */
2011                 if (nsbp->sb_rextsize != sbp->sb_rextsize)
2012                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
2013                                 nsbp->sb_rextsize - sbp->sb_rextsize);
2014                 if (nsbp->sb_rbmblocks != sbp->sb_rbmblocks)
2015                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
2016                                 nsbp->sb_rbmblocks - sbp->sb_rbmblocks);
2017                 if (nsbp->sb_rblocks != sbp->sb_rblocks)
2018                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
2019                                 nsbp->sb_rblocks - sbp->sb_rblocks);
2020                 if (nsbp->sb_rextents != sbp->sb_rextents)
2021                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
2022                                 nsbp->sb_rextents - sbp->sb_rextents);
2023                 if (nsbp->sb_rextslog != sbp->sb_rextslog)
2024                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
2025                                 nsbp->sb_rextslog - sbp->sb_rextslog);
2026                 /*
2027                  * Free new extent.
2028                  */
2029                 bp = NULL;
2030                 error = xfs_rtfree_range(nmp, tp, sbp->sb_rextents,
2031                         nsbp->sb_rextents - sbp->sb_rextents, &bp, &sumbno);
2032                 if (error) {
2033 error_cancel:
2034                         xfs_trans_cancel(tp, cancelflags);
2035                         break;
2036                 }
2037                 /*
2038                  * Mark more blocks free in the superblock.
2039                  */
2040                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS,
2041                         nsbp->sb_rextents - sbp->sb_rextents);
2042                 /*
2043                  * Update mp values into the real mp structure.
2044                  */
2045                 mp->m_rsumlevels = nrsumlevels;
2046                 mp->m_rsumsize = nrsumsize;
2047
2048                 error = xfs_trans_commit(tp, 0);
2049                 if (error)
2050                         break;
2051         }
2052
2053         /*
2054          * Free the fake mp structure.
2055          */
2056         kmem_free(nmp);
2057
2058         return error;
2059 }
2060
2061 /*
2062  * Allocate an extent in the realtime subvolume, with the usual allocation
2063  * parameters.  The length units are all in realtime extents, as is the
2064  * result block number.
2065  */
2066 int                                     /* error */
2067 xfs_rtallocate_extent(
2068         xfs_trans_t     *tp,            /* transaction pointer */
2069         xfs_rtblock_t   bno,            /* starting block number to allocate */
2070         xfs_extlen_t    minlen,         /* minimum length to allocate */
2071         xfs_extlen_t    maxlen,         /* maximum length to allocate */
2072         xfs_extlen_t    *len,           /* out: actual length allocated */
2073         xfs_alloctype_t type,           /* allocation type XFS_ALLOCTYPE... */
2074         int             wasdel,         /* was a delayed allocation extent */
2075         xfs_extlen_t    prod,           /* extent product factor */
2076         xfs_rtblock_t   *rtblock)       /* out: start block allocated */
2077 {
2078         int             error;          /* error value */
2079         xfs_inode_t     *ip;            /* inode for bitmap file */
2080         xfs_mount_t     *mp;            /* file system mount structure */
2081         xfs_rtblock_t   r;              /* result allocated block */
2082         xfs_fsblock_t   sb;             /* summary file block number */
2083         xfs_buf_t       *sumbp;         /* summary file block buffer */
2084
2085         ASSERT(minlen > 0 && minlen <= maxlen);
2086         mp = tp->t_mountp;
2087         /*
2088          * If prod is set then figure out what to do to minlen and maxlen.
2089          */
2090         if (prod > 1) {
2091                 xfs_extlen_t    i;
2092
2093                 if ((i = maxlen % prod))
2094                         maxlen -= i;
2095                 if ((i = minlen % prod))
2096                         minlen += prod - i;
2097                 if (maxlen < minlen) {
2098                         *rtblock = NULLRTBLOCK;
2099                         return 0;
2100                 }
2101         }
2102         /*
2103          * Lock out other callers by grabbing the bitmap inode lock.
2104          */
2105         if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
2106                                         XFS_ILOCK_EXCL, &ip)))
2107                 return error;
2108         sumbp = NULL;
2109         /*
2110          * Allocate by size, or near another block, or exactly at some block.
2111          */
2112         switch (type) {
2113         case XFS_ALLOCTYPE_ANY_AG:
2114                 error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
2115                                 &sumbp, &sb, prod, &r);
2116                 break;
2117         case XFS_ALLOCTYPE_NEAR_BNO:
2118                 error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
2119                                 len, &sumbp, &sb, prod, &r);
2120                 break;
2121         case XFS_ALLOCTYPE_THIS_BNO:
2122                 error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen,
2123                                 len, &sumbp, &sb, prod, &r);
2124                 break;
2125         default:
2126                 ASSERT(0);
2127         }
2128         if (error) {
2129                 return error;
2130         }
2131         /*
2132          * If it worked, update the superblock.
2133          */
2134         if (r != NULLRTBLOCK) {
2135                 long    slen = (long)*len;
2136
2137                 ASSERT(*len >= minlen && *len <= maxlen);
2138                 if (wasdel)
2139                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -slen);
2140                 else
2141                         xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -slen);
2142         }
2143         *rtblock = r;
2144         return 0;
2145 }
2146
2147 /*
2148  * Free an extent in the realtime subvolume.  Length is expressed in
2149  * realtime extents, as is the block number.
2150  */
2151 int                                     /* error */
2152 xfs_rtfree_extent(
2153         xfs_trans_t     *tp,            /* transaction pointer */
2154         xfs_rtblock_t   bno,            /* starting block number to free */
2155         xfs_extlen_t    len)            /* length of extent freed */
2156 {
2157         int             error;          /* error value */
2158         xfs_inode_t     *ip;            /* bitmap file inode */
2159         xfs_mount_t     *mp;            /* file system mount structure */
2160         xfs_fsblock_t   sb;             /* summary file block number */
2161         xfs_buf_t       *sumbp;         /* summary file block buffer */
2162
2163         mp = tp->t_mountp;
2164         /*
2165          * Synchronize by locking the bitmap inode.
2166          */
2167         if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
2168                                         XFS_ILOCK_EXCL, &ip)))
2169                 return error;
2170 #if defined(__KERNEL__) && defined(DEBUG)
2171         /*
2172          * Check to see that this whole range is currently allocated.
2173          */
2174         {
2175                 int     stat;           /* result from checking range */
2176
2177                 error = xfs_rtcheck_alloc_range(mp, tp, bno, len, &stat);
2178                 if (error) {
2179                         return error;
2180                 }
2181                 ASSERT(stat);
2182         }
2183 #endif
2184         sumbp = NULL;
2185         /*
2186          * Free the range of realtime blocks.
2187          */
2188         error = xfs_rtfree_range(mp, tp, bno, len, &sumbp, &sb);
2189         if (error) {
2190                 return error;
2191         }
2192         /*
2193          * Mark more blocks free in the superblock.
2194          */
2195         xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, (long)len);
2196         /*
2197          * If we've now freed all the blocks, reset the file sequence
2198          * number to 0.
2199          */
2200         if (tp->t_frextents_delta + mp->m_sb.sb_frextents ==
2201             mp->m_sb.sb_rextents) {
2202                 if (!(ip->i_d.di_flags & XFS_DIFLAG_NEWRTBM))
2203                         ip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
2204                 *(__uint64_t *)&ip->i_d.di_atime = 0;
2205                 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2206         }
2207         return 0;
2208 }
2209
2210 /*
2211  * Initialize realtime fields in the mount structure.
2212  */
2213 int                             /* error */
2214 xfs_rtmount_init(
2215         xfs_mount_t     *mp)    /* file system mount structure */
2216 {
2217         xfs_buf_t       *bp;    /* buffer for last block of subvolume */
2218         xfs_daddr_t     d;      /* address of last block of subvolume */
2219         xfs_sb_t        *sbp;   /* filesystem superblock copy in mount */
2220
2221         sbp = &mp->m_sb;
2222         if (sbp->sb_rblocks == 0)
2223                 return 0;
2224         if (mp->m_rtdev_targp == NULL) {
2225                 cmn_err(CE_WARN,
2226         "XFS: This filesystem has a realtime volume, use rtdev=device option");
2227                 return XFS_ERROR(ENODEV);
2228         }
2229         mp->m_rsumlevels = sbp->sb_rextslog + 1;
2230         mp->m_rsumsize =
2231                 (uint)sizeof(xfs_suminfo_t) * mp->m_rsumlevels *
2232                 sbp->sb_rbmblocks;
2233         mp->m_rsumsize = roundup(mp->m_rsumsize, sbp->sb_blocksize);
2234         mp->m_rbmip = mp->m_rsumip = NULL;
2235         /*
2236          * Check that the realtime section is an ok size.
2237          */
2238         d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
2239         if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_rblocks) {
2240                 cmn_err(CE_WARN, "XFS: realtime mount -- %llu != %llu",
2241                         (unsigned long long) XFS_BB_TO_FSB(mp, d),
2242                         (unsigned long long) mp->m_sb.sb_rblocks);
2243                 return XFS_ERROR(EFBIG);
2244         }
2245         bp = xfs_buf_read_uncached(mp, mp->m_rtdev_targp,
2246                                         d - XFS_FSB_TO_BB(mp, 1),
2247                                         XFS_FSB_TO_B(mp, 1), 0);
2248         if (!bp) {
2249                 cmn_err(CE_WARN, "XFS: realtime device size check failed");
2250                 return EIO;
2251         }
2252         xfs_buf_relse(bp);
2253         return 0;
2254 }
2255
2256 /*
2257  * Get the bitmap and summary inodes into the mount structure
2258  * at mount time.
2259  */
2260 int                                     /* error */
2261 xfs_rtmount_inodes(
2262         xfs_mount_t     *mp)            /* file system mount structure */
2263 {
2264         int             error;          /* error return value */
2265         xfs_sb_t        *sbp;
2266
2267         sbp = &mp->m_sb;
2268         if (sbp->sb_rbmino == NULLFSINO)
2269                 return 0;
2270         error = xfs_iget(mp, NULL, sbp->sb_rbmino, 0, 0, &mp->m_rbmip);
2271         if (error)
2272                 return error;
2273         ASSERT(mp->m_rbmip != NULL);
2274         ASSERT(sbp->sb_rsumino != NULLFSINO);
2275         error = xfs_iget(mp, NULL, sbp->sb_rsumino, 0, 0, &mp->m_rsumip);
2276         if (error) {
2277                 IRELE(mp->m_rbmip);
2278                 return error;
2279         }
2280         ASSERT(mp->m_rsumip != NULL);
2281         return 0;
2282 }
2283
2284 void
2285 xfs_rtunmount_inodes(
2286         struct xfs_mount        *mp)
2287 {
2288         if (mp->m_rbmip)
2289                 IRELE(mp->m_rbmip);
2290         if (mp->m_rsumip)
2291                 IRELE(mp->m_rsumip);
2292 }
2293
2294 /*
2295  * Pick an extent for allocation at the start of a new realtime file.
2296  * Use the sequence number stored in the atime field of the bitmap inode.
2297  * Translate this to a fraction of the rtextents, and return the product
2298  * of rtextents and the fraction.
2299  * The fraction sequence is 0, 1/2, 1/4, 3/4, 1/8, ..., 7/8, 1/16, ...
2300  */
2301 int                                     /* error */
2302 xfs_rtpick_extent(
2303         xfs_mount_t     *mp,            /* file system mount point */
2304         xfs_trans_t     *tp,            /* transaction pointer */
2305         xfs_extlen_t    len,            /* allocation length (rtextents) */
2306         xfs_rtblock_t   *pick)          /* result rt extent */
2307 {
2308         xfs_rtblock_t   b;              /* result block */
2309         int             error;          /* error return value */
2310         xfs_inode_t     *ip;            /* bitmap incore inode */
2311         int             log2;           /* log of sequence number */
2312         __uint64_t      resid;          /* residual after log removed */
2313         __uint64_t      seq;            /* sequence number of file creation */
2314         __uint64_t      *seqp;          /* pointer to seqno in inode */
2315
2316         if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
2317                                         XFS_ILOCK_EXCL, &ip)))
2318                 return error;
2319         ASSERT(ip == mp->m_rbmip);
2320         seqp = (__uint64_t *)&ip->i_d.di_atime;
2321         if (!(ip->i_d.di_flags & XFS_DIFLAG_NEWRTBM)) {
2322                 ip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
2323                 *seqp = 0;
2324         }
2325         seq = *seqp;
2326         if ((log2 = xfs_highbit64(seq)) == -1)
2327                 b = 0;
2328         else {
2329                 resid = seq - (1ULL << log2);
2330                 b = (mp->m_sb.sb_rextents * ((resid << 1) + 1ULL)) >>
2331                     (log2 + 1);
2332                 if (b >= mp->m_sb.sb_rextents)
2333                         b = do_mod(b, mp->m_sb.sb_rextents);
2334                 if (b + len > mp->m_sb.sb_rextents)
2335                         b = mp->m_sb.sb_rextents - len;
2336         }
2337         *seqp = seq + 1;
2338         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
2339         *pick = b;
2340         return 0;
2341 }